According to an October 20th Food Safety Alert, the Centers for Disease Control and Prevention have positively identified whole red, white and yellow onions imported from Chihuahua, Mexico as the vehicle of infection for an extensive Salmonella Oranienburg outbreak.  The source is a national distributer, ProSource Inc. located in Hailey, Idaho.

Since the first case was identified during the first week of September, 652 illness have been diagnosed although it is accepted that this is only a small proportion of those actually infected.  There have been 129 hospitalizations representing a 20 percent rate. but fortunately no fatalities.  Cases have been identified in thirty-seven states ranging from California to Massachusetts with the highest numbers in Texas, Oklahoma, Virginia and Illinois. Consumers in California, New Mexico, Nebraska, South Dakota, Michigan, Ohio and Pennsylvania were less affected.

CDC isolated the outbreak strain of Salmonella Oranienburg from a sample in a restaurant followed by trace-back to ProSource Inc.  The distributor agreed to recall the affected batch of onions with import dates from July 1st through August 27th.  It is possible that since onions have a long shelf life, potentially contaminated product will remain in household pantries for additional weeks although recall from restaurants and institutions should be implemented with minimal delays.

Although the source of vehicle has been identified, it is apparent that factors that contributed to contamination in Mexico obviously still exist, and surveillance is indicated given the impossibility of preventing contamination of produce using current methods of cultivation and packing.

In 2020 Thompson International located in the Imperial Valley of California was confirmed as the source of a Salmonella Newport outbreak with 1,600 diagnosed cases in the U.S and Canada. The vehicle of infection was identified as red onions irrigated with water contaminated by sheep feces. Investigation of the current outbreak will probably reveal irrigation water contaminated wit ruminant feces complicated by persistence of the pathogen in packing facilities.